Blending efficiency of Reclaimed Asphalt Pavement: An approach utilizing rheological properties and molecular weight distributions

Different mixing conditions are expected to have a large influence on the ability for Reclaimed Asphalt Pavement (RAP) and virgin binder to blend in an asphalt pavement mixture. This study investigates the influence of mixing time, mixing temperature, and the inclusion of Warm Mix Asphalt (WMA) additives on the ability to RAP and virgin binder to blend. A large virgin aggregate and a small RAP were blended with virgin binder in defined mixing scenarios. The aggregates were then separated, the binder was recovered, and the rheological and chemical properties were investigated using the Dynamic Shear Rheometer (DSR) and Gel Permeation Chromatography (GPC). This research found that there is a limit to which mixing time has an influence on binder blending, mixing temperature may have a significant effect, and the inclusion of WMA additives has a positive effect on blending.